1. Field of the Invention
The present invention relates to a three-dimensional object identifying system for identifying a three-dimensional-shape object optically. For example, the invention is concerned with a three-dimensional object identifying system for identifying a part of a human body in order to prevent an information apparatus such as a personal computer from being used illegitimately by a user other than a legitimate user thereof.
2. Description of the Prior Art
Heretofore, as a three-dimensional object identifying system for identifying a three-dimensional-shape object, there has been known a system in which a three-dimensional shape is inputted from an object and the object is identified on the basis of the three-dimensional shape. As an input device for inputting a three-dimensional shape from an object, there has been used practically or proposed an input device wherein a three-dimensional shape of an object is inputted from a displacement (i.e., parallax) of images obtained from plural cameras or an input device wherein a slit light or a laser spot light is scanned and radiated to a three-dimensional object, then the reflected image is taken in and a three-dimensional shape of the object is inputted.
For example, a method of recognizing a three-dimensional shape with use of two cameras is described in Japanese Published Unexamined Patent Application No. Hei 6-3122. According to this method, a three-dimensional information of an object to be measured is photographed with use of two cameras and in accordance with image signals obtained from the cameras a parallax is converted to a color distribution using two liquid crystal displays and prism, thereby recognizing the height, etc. of the object.
A method which comprises scanning and radiating a laser spot light and inputting a three-dimensional shape is described in Japanese Published Unexamined Patent Application No. Hei 6-201342. According to this method, a monochromatic laser spot light of RGB is scanned and radiated to an object to be measured and the distance and color of the object are taken in exactly on the basis of displacement of the observation position obtained by resolving the RGB components on a detection side. According to this method, moreover, a radiation light is modulated with a modulation signal to improve the selection accuracy on the detection side of the monochromatic light of RGB, thereby making it possible to acquire required information accurately even in the event of a sudden change in the surface shape or color of the object.
Further, a proximity sensor is described in Japanese Published Examined Patent Application No. Sho 62-44206 in which light rays are radiated to an object from a pair of light sources adapted to be driven with repeat signals which are 90xc2x0 out of phase with each other, then reflected light rays of the radiated light rays from the object are received by a light receiving element, and the distance between the light receiving element and the object is detected on the basis of the phase difference. By scanning this proximity sensor over a three-dimensional object through a mechanical part such as a robot arm, the input of a three-dimensional shape can be implemented with a simple sensor structure.
In all of the above three-dimensional object inputting methods, the three-dimensional object is inputted as a three-dimensional image or as a distance image obtained by imaging the distance from a reference position. For identifying the three-dimensional object, it is necessary that the three-dimensional images obtained by the above methods be further subjected to identifying processing.
As to the identification processing, for example in Japanese Published Unexamined Patent Application No. Hei 2-181880 there is described a method wherein a local surface of a distance image is taken out, then an approximate expression of the surface is obtained by a least squares method, and coefficients of the approximate expression are evaluated to detect a three-dimensional shape. Also other than this method there have been proposed and adopted actually a large number of methods for identifying a three-dimensional shape, in all of which a three-dimensional shape of a three-dimensional object is inputted accurately as data and the three-dimensional object is identified in accordance with the data of the three-dimensional shape.
Three-dimensional object identifying systems include systems which identify a part of a human body as a three-dimensional object. For example, Handkey-Hand Reader (trade name) of RECOGNITION SYSTEMS, INC., in the U.S. permits identifying an individual from the shape of a human hand. For identifying an individual by using this system, the user is required to put his or her hand into the system.
In Japanese Published Unexamined Patent Application No. Hei 10-94534 is disclosed an individual identifying system using a special instrument which detects a three-dimensional shape of an auricle through a plurality of light emitting portions and a plurality of light receiving portions. In this system, the plural light emitting portions disposed within the special instrument are allowed to emit light successively, then the lights reflected from the auricle are detected by the light receiving portions, and the individual is identified from a time series-like pattern of detected signals. In the event an extraneous light which changes with time, say, an illumination light from an AC-lit fluorescent lamp or light from a CRT (Cathode-RayTube) for display, is mixed into the light receiving portions, an influence is exerted on the time series-like signal pattern in the light receiving portions which underlies the identification, and thus it is impossible to effect accurate identification. Consequently, it is required to use some light shielding member.
Thus, in the above two systems for identifying a part of a human body as a three-dimensional object, the user is required to perform some troublesome operation or use a special instrument at the time of identifying an individual.
In the above conventional three-dimensional object identifying systems it is necessary to input a three-dimensional shape of an object accurately and identify the thus-acquired three-dimensional shape accurately by electronic or optical processing. Since the processing is complicated, there arises the problem that the systems become complicated and become larger in size. In addition, in the case of inputting a three-dimensional shape optically, it is necessary in many cases to define environmental conditions such as exterior lighting conditions, and the system concerned is sometimes unemployable in environmental conditions in which there is used such an information apparatus as a personal computer, for example, in an office or in a home.
In the above conventional system which uses a human hand for identifying a legitimate user of an information apparatus such as a personal computer, the size of the system is too large for attachment thereof to such an information apparatus as a personal computer. Further, the user is required to put his or her hand consciously into the system and put it at a predetermined position, thus giving rise to the problem that the user is given a sense of incongruity.
In the above conventional system which identifies an individual on the basis of the shape of an auricle, the user is required to attach a special instrument to his or her ear at the time of the identifying operation, and here again the use will have a sense of incongruity.
It is a purpose of the present invention to provide a three-dimensional object identifying system which is small-sized and simple in construction and which can identify a three-dimensional object. It is another purpose of the present invention to provide a three-dimensional object identifying system capable of identifying an individual without giving a sense of incongruity to a user.
According to the present invention, the above purposes can be achieved by a three-dimensional object identifying system comprising a signal generating part that generates a modulation signal, a light emitting part that emits light based on the modulation signal to a three-dimensional object, a light receiving part that receives light reflected from the three-dimensional object and produces a detection signal, a detecting part that detects a correlation information of the detection signal and the modulation signal, and identifying part that performs an identifying processing for the three-dimensional object in accordance with pre-cataloged correlation information and the detected correlation information.
According to the present invention, the above purposes can be achieved by a three-dimensional object identifying system combined with the above system, wherein the light emitting part and the light receiving part are incorporated in a user interface device of an information apparatus.
Further, according to the present invention, the above purposes can be achieved by an information apparatus comprising a general-purpose input part that performs input of information responsive to an input operation of an input operator, a processing unit that processes the information inputted from the general-purpose input part, a light emitting part that radiates light to the input operator, a light receiving part that receives reflected light from the input operator, and an identifying part that acquires from the light receiving part light intensity information proportional to a body posture of the input operator when using the input part and which performs identifying processing for the input operator in accordance with the light intensity information and cataloged information.